Imaging device and plate spring

ABSTRACT

Disclosed herein is an imaging device including: a lens case on which a lens is installed; a columnar member having a central axis coincidental with a rotational axis of the lens case and formed on a lateral surface of the lens case, the rotational axis extending in a tilt direction being an in-plane direction perpendicular to a horizontal direction; a base supporting the lens case so as to be turnable in the tilt direction; and a plate spring secured to the base and pressing a circumferential surface of the columnar member toward the base by elastic force.

BACKGROUND

The present technology relates to an imaging device and a plate spring.

Imaging devices such as security cameras and the like are used to take a picture of surrounding environment but have a fixed installation position. Therefore, a lens of the imaging device is desirably moved horizontally and vertically depending on the relationship between a range capable of being shot through the lens installed in the security camera and a site to be shot by a user by use of the security camera. Incidentally, the horizontal movement of a lens is referred to as the movement in a pan direction and the vertical movement of the lens is referred to as the movement in a tilt direction.

A security camera is generally composed of a lens block or a member including a lens and a support member for supporting the lens block and securing a main body to a ceiling or the like in a room. In this case, the lens block can be moved in pan and tilt directions with respect to the support member.

SUMMARY

A lens block has heretofore been positioned in pan and tilt directions by e.g. a ball joint, a universal joint or the like. However, such a mechanism has a complicated structure and needs a large space for installation of component parts. In addition, such a structure needs a large number of screws for the installation of the component parts. Consequently, it is hard to achieve downsizing and cost reduction in the manufacture of the imaging device.

It is desirable to provide a noble and improved imaging device and plate spring that can achieve the downsizing of the whole, and change the direction of a lens and secure the position of the lens with a simple configuration.

According to an embodiment of the present disclosure, there is provided an imaging device including: a lens case on which a lens is installed; a columnar member having a central axis coincidental with a rotational axis of the lens case and formed on a lateral surface of the lens case, the rotational axis extending in a tilt direction being an in-plane direction perpendicular to a horizontal direction; a base supporting the lens case so as to be turnable in the tilt direction; and a plate spring secured to the base and pressing a circumferential surface of the columnar member toward the base by elastic force.

The plate spring may have a first bent portion pressing the circumferential surface of a columnar member toward the base.

The plate spring may further have a plate-like insertion portion, and the base may have a first opening adapted to receive the insertion portion inserted thereinto to secure the plate spring.

The imaging device may further include a cover allowing the lens to be exposed and covering the lens case, the columnar member, the base and the plate spring; and the plate spring may secure the cover to the base by elastic force.

The cover may support the lens case turnably in the tilt direction.

The plate spring may have a second bent portion securing the cover to the base.

The cover may have a second opening adapted to receive the plate spring inserted thereinto and a guide portion guiding the plate spring to the second opening.

According to another embodiment of the present disclosure, there is provided a plate spring including: a first spring portion pressing a circumferential surface of a columnar member toward a base supporting the lens case, the columnar member being formed on a lateral surface of a lens case on which a lens is installed; and a second spring portion securing a cover to the base by elastic force, the cover covering the lens case, the columnar member and the base while allowing the lens to be exposed.

The plate spring may further include a plate-like insertion portion inserted into a first opening formed in the base.

The present disclosure described above can downsize the whole of the device and change and fix the direction and position of the lens with the simple configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a security camera according to an embodiment of the present disclosure;

FIG. 2 is a lateral view of the security camera according to the embodiment;

FIG. 3 is a perspective view of the security camera according to the embodiment with an exterior cover removed;

FIG. 4 is an exploded perspective view of the security camera shown in FIG. 3;

FIG. 5 is an exploded lateral view of the security camera shown in FIG. 3;

FIG. 6 is an exploded lateral view of the security camera shown in FIG. 3;

FIG. 7 is an exploded perspective view of the security camera according to the embodiment with exterior covers removed;

FIG. 8 is an exploded perspective view of a lens block;

FIG. 9 is a plan view of a pan plate spring;

FIG. 10 is a lateral view of the pan plate spring;

FIG. 11 is a plan view of a tilt plate spring;

FIG. 12 is a lateral view of the tilt plate spring;

FIG. 13 is a lateral view of the tilt plate spring;

FIG. 14 is a perspective view of the exterior cover;

FIG. 15 is a bottom view of the exterior cover; and

FIG. 16 is a partial enlarged view of FIG. 6, illustrating a state where the tilt plate spring holds a projecting portion of a lens case.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present disclosure will hereinafter be described in detail with reference to the accompanying drawings. Incidentally, in the present specification and drawings, constituent elements having substantially identical functional configurations are denoted with like reference numerals and their duplicate explanations are omitted.

Descriptions are given in the following order.

1. A configuration in an embodiment

2. An assembly method in the embodiment

3. An adjustment method in the embodiment

<1. Configuration in the Embodiment>

A description is first given of a security camera 100 according to an embodiment of the present disclosure.

The security camera 100 is secured to a horizontal plane such as e.g. a ceiling of a room or the like. The security camera 100 takes photos of surrounding environment as moving images or still images. As illustrated in FIGS. 1 and 2, a lens 108 c of the security camera 100 can manually be shifted in horizontal and vertical directions. Incidentally, the horizontal movement of the lens 108 c is referred to as the movement in a pan direction and the vertical movement of the lens 108 c is referred to as the movement in a tilt direction. Adjusting the position of the lens 108 c installed in the security camera 100 can take a photo of a site to be shot by a user with the security camera 100 regardless of a range capable of being shot through the lens 108 c.

The security camera 100 includes a lens block 101 covered by an exterior cover 107; an lower case 103 covered by the exterior cover 109; and a circuit board 104, on which electronic parts such as circuits required to operate the security camera 100 are mounted.

Referring to FIG. 7, the lens block 101 is composed of a base 105 and a lens case 108. A description is first given of the lens block 101.

The base 105 is made of e.g. a synthetic resin. Referring to FIG. 8, lens case support portions 105 b support the lens case 108 so as to be turnable in the tilt direction. The lens case support portion 105 b has a circumferential surface, which corresponds to the circumferential surface of a slide portion 108 a of the lens case 108. In this way, the lens case 108 can smoothly travel in the tilt direction. The base 105 is put on three projecting portions 103 a and turned thereon in the pan direction. In addition, the base 105 supports the lens case 108 so as to be turnable in the pan direction. Further, the base 105 has an outer circumferential portion 105 a formed in a circular cylindrical shape. The outer circumferential portion 105 a is pressed against the lower case 103 side by a pan plate spring 102.

The lens case 108 is made of e.g. a synthetic resin. In addition, the lens 108 c is installed on the lens case 108. A CCD (Charge Coupled Device) imaging element or a CMOS (Complementary Metal Oxide Semiconductor) imaging element or other electric parts are installed inside the lens case 108; however, illustration is omitted in the figures. The CCD imaging element or the CMOS imaging element is adapted to focus light passing through the lens 108 c into an image and subject the image to photoelectric conversion to create signals. The lens case 108 is formed with projecting portions 108 b on its lateral surfaces. The projecting portion 108 b is an example of a columnar member and has a central axis coincident with the tilt-directional rotational axis of the lens case 108. The lens case 108 can be turned in the tilt direction on the base 105.

A tilt plate spring 106 is made of e.g. metal. The tilt plate spring 106 is secured to the base 105 and presses the circumferential surface of the projecting portion 108 b of the lens case 108 toward the base 105 by elastic force. The tilt plate spring 106 secures the exterior cover 107 to the base 105 by the elastic force.

The tilt plate spring 106 includes bent portions 106 a, 106 b and an inserting portion 106 c. The bent portion 106 a is an example of a first bent portion and presses the circumferential surface of the projecting portion 108 b toward the base 105 by the elastic force of the plate spring. The bent portion 106 b is an example of a second bent portion. In addition, the bent portions 106 b are inserted into corresponding securing holes 107 a of the exterior cover 107 to secure the exterior cover 107 to the base 105 by the elastic force of the plate spring. The inserting portion 106 c is formed like a plate. In addition, the inserting portion 106 c is formed with an insertion side end portion on the bent portion 106 a side and is inserted into an insertion hole 105 c of the base 105. Consequently, the tilt plate spring 106 is secured to the base 105.

The pan plate spring 102 is made of e.g. metal. In addition, the plate spring 102 presses the base 105 toward the lower case 103 by elastic force. The pan plate spring 102 includes spring portions 102 c, a circular portion 102 d, and retaining portions 102 e. The circular portion 102 d is a thin plate and has a ring shape. The base 105 is inserted into the inner circumference of the circular portion 102 d. Since the circular portion 102 d is formed with cutout portions 102 f at its inner circumference, the spring portion 102 c has appropriate elastic force and presses the outer circumferential portion 105 a of the base 105 by the elastic force. The retaining portion 102 e is formed by being bent from the outer circumference of the circular portion 102 d and retains the corresponding projecting portion 103 a.

In the state where the security camera 100 is assembled, the lens block 101 is pressed by the pan plate spring 102 against the projecting portions 103 a of the lower case 103 serving as a chassis of the security camera 100. The outer circumferential portion 105 a of the base 105 of the lens block 101 is put on respective cutout portions 103 aA of the projecting portions 103 a formed on the lower case 103 to thereby position the base 105. Incidentally, the projecting portion 103 a is provided with a column-shaped rib 103 aB on its upper surface and with a square rib 103 aC on its lateral surface.

The pan plate spring 102 is provided with positioning holes 102 a and square holes 102 b. The positioning holes 102 a determine the position of the pan plate spring 102. The square holes 102 b are adapted to secure the pan plate spring 102. Further, the spring portions 102 c each having such a shape as to press the lens block 101 are each formed on the inside of the pan plate spring 102 by the corresponding cutout portions 102 f.

The exterior cover 107 covers the lens block 101. The exterior cover 107 is formed with a lens opening portion 107 b. The lens opening portion 107 b is opened in the exterior cover 107 in a tilt-directional shifting range of the lens 108 c so that the lens 108 c may be exposed. As shown in FIGS. 14 and 15, lens case support portions 107 c are formed inside the exterior cover 107. The lens case support portion 107 c has a circular surface, which corresponds to a circular surface of the slide portion 108 a of the lens case 108. In this way, the lens case 108 can smoothly be shifted in the tilt direction.

Further, guide portions 107 e and restricting portions 107 d are provided inside the exterior cover 107. When the exterior cover 107 is secured to the base 105, the guide portions 107 e come into contact with the corresponding bent portions 106 b of the tilt plate spring 106. While coming into contact with the guide portions 107 e, the bent portions 106 b are guided to the corresponding securing holes 107 a of the exterior cover 107. When the exterior cover 107 is secured to the base 105, the restricting portions 107 d come into contact with corresponding lateral surfaces of the bent portions 106 b of the tilt plate spring 106. The restricting portion 107 d restricts the outward widening of the bent portion 106 b. In this way, the guide portions 107 e and the restricting portions 107 d smoothly guide the bent portions 106 b of the tilt plate spring 106 into the corresponding securing holes 107 a of the exterior cover 107.

<2. Assembling Method in the Embodiment>

A description is next given of a method of assembling the security camera 100 in the present embodiment.

The circuit board 104 is installed on the lower case 103. The circuit board 104 is secured by a single screw not shown and the hooks 103 b formed on the lower case 103 shown in FIG. 4.

The base 105 of the lens block 101 is put on the cutout portions 103 aA formed on the projecting portions 103 a of the lower case 103.

The pan plate spring 102 is next covered to hold the base 105. In addition, the positioning holes 102 a are aligned with the corresponding column-shaped ribs 103 aB shown in FIG. 7. Consequently, the position of the pan plate spring 102 is determined. Further, the pan plate spring 102 is pushed so that the square holes 102 b are fitted to the corresponding ribs 103 aC shown in FIG. 7. In this state, the pan plate spring 102 holds the base 105 by means of the three spring portions 102 c formed inside the pan plate spring 102. The spring portion 102 c has a function of a cantilever thin-plate spring. Thus, the base 105 is pressed against the cutout portions 103 aA of the lower case 103 by means of the three spring portions 102 c.

There are a plurality of the methods of increasing or decreasing the elastic force of the pan plate spring 102 in the embodiment. The methods have an advantage that it is easy to adjust the magnitude of the elastic force. Examples of the method of increasing or decreasing the elastic force include a method of increasing or decreasing the thickness of the pan plate spring 102, a method of increasing or decreasing the hardness of a material of the plate spring, a method of increasing or decreasing the size of the spring portion 102 c, and a method of increasing or decreasing the thickness of the outer circumferential portion 105 a of the base 105.

With the shape of the pan plate spring 102 in the present embodiment, the three retaining portions 102 e provided at nearly regular intervals on the outer circumference of the circular portion 102 d are fitted to the corresponding ribs 103 aC of the lower case 103. Consequently, the elastic force of the spring portions 102 c is applied to the square holes 102 b of the three retaining portions 102 e. Therefore, the square holes 102 b are individually subjected to force in a direction where the pan plate spring 102 comes free from the lower case 103 by the elastic force caused by the spring portion 102 c closed to the associated square hole 102 b. However, such forces pull each other because the three retaining portions 102 e are connected to each other via the circular portion 102 d. Therefore, the pan plate spring 102 will not come free from the lower case 103. Thus, it is not necessary to secure the pan plate spring 102 to the lower case 103 by means of screws or the like.

Further, with the above-mentioned configuration and the shape of the pan plate spring 102, the mechanism for turning the lens block 101 in the pan direction (the arrow direction in FIG. 1) has only the base 105 having such a shape that the lens case 108 will not slide in the pan direction on the base 105, and the pan plate spring 102. Therefore, a complicated mechanism is not necessary unlike the traditional way and screws or the like are not necessary to secure the pan plate spring 102. Thus, the security camera 100 can achieve space saving.

The lens case 108 is put on the base 105. The lens case 108 is formed with the slide portions 108 a on both the lateral surfaces. The slide portions 108 a cause the lens case 108 to be turned in the tilt direction. The base 105 is formed with the lens case support portions 105 b shaped to receive the corresponding slide portions 108 a.

The tilt plate spring 106 is next inserted into the insertion holes 105 c of the base 105 shown in FIG. 8 in the state where the bent portion 106 a holds the projecting portion 108 b of the lens case 108. Incidentally, the tilt plate spring 106 is similarly inserted into the base 105 also on the opposite surface side not shown in FIG. 8.

In this state, the lens case 108 and the base 105 are united with each other via the tilt plate spring 106. Since the bent portion 106 a holds the projecting portion 108 b of the lens case 108, a thin-plate portion supporting the bent portion 106 a serves as a cantilever thin-plate spring. The elastic force of the thin-plate spring serves as a load when the lens case 108 is turned based on the slide portion 108 a. As a result, the elastic force of the tilt plate spring 106 serves as force adapted to hold the lens 108 c at a position in the tilt direction.

Incidentally, if the slide portion 108 a and the projecting portion 108 b are formed separately from each other, there is an advantage as below. The contact with the tilt plate spring 106 may damage the projecting portion 108 b of the lens case 108. Even in such a case, the slide surface in the tilt direction is the surface of the slide portion 108 a different from the projecting portion 108 b coming into contact with the tilt plate spring 106. Therefore, the movement in the tilt direction can be maintained. The slide portion 108 a having a greater diameter can stabilize the movement in the slide direction. The projecting portion 108 b having a smaller diameter can downsize the tilt plate spring 106.

There are a plurality of the method of increasing or decreasing the elastic force of the tilt plate spring 106 in the present embodiment. The method has an advantage that it is easy to adjust the magnitude of the elastic force. Examples of the methods of increasing or decreasing the elastic force include a method of increasing or decreasing the thickness of the tilt plate spring 106, a method of increasing or decreasing the hardness of a material of the plate spring, a method of increasing or decreasing an bending angle of the bent portion 106 a, and a method of increasing or decreasing the diameter of the projecting portion 108 b of the lens case 108.

The tilt plate spring 106 is inserted in a direction perpendicular to the vertical direction encountered during installation. The tilt plate spring 106 presses the lens case 108 toward the base 105 side. Therefore, the tilt plate spring 106 will not come off in the vertical direction encountered during the installation. On the other hand, the tilt plate spring 106 can easily be removed in the inserting direction.

Also another bent portion 106 b of the tilt plate spring 106 is such that a thin-plate portion supporting the bent portion 106 b serves as a plate spring. The bent portion 106 b is inserted into the securing hole 107 a of the exterior cover 107. In this way, the exterior cover 107 is united with the base 105. Also the insertion direction of the tilt plate spring 106 into the securing hole 107 a is a direction perpendicular to the vertical direction encountered during the installation.

With the configuration described above, the tilt plate spring 106 is secured by being held between the base 105 and he exterior cover 107. Thus, it is not necessary to secure the tilt plate spring 106 by means of a screw or the like.

As above, the security camera 100 can be easily assembled only by overlapping the lower case 103, the circuit board 104, the lens block 101, and the pan plate spring 102 in order.

<3. Adjusting Method in the Embodiment>

A description is given of a method of adjusting the lens 108 c of the security camera 100 in the present embodiment.

[Pan Direction]

If the lens block 101 is to be manually turned in the pan direction indicated with arrows in FIG. 1, the spring portion 102 c of the pan plate spring 102 serves as a load. If the lens block 101 is turned by a force equal to or greater than the load and one's hand is released from the lens block 101 when the lens 108 c faces a desired direction, the lens 108 c is stopped at the position. The holding force of the lens block 101 in this state corresponds to the elastic force of the spring portion 102 c of the pan plate spring 102.

The elastic force is increased or decreased by the plurality of methods as described above, which are simple In the embodiment, the elastic force is studied as the rotational moment of the lens block 101 and set at 50 to 100 Nmm. This value is determined depending on the weight, size and the like of the lens block 101. Therefore, the fact that there is a plurality of the methods of increasing or decreasing the elastic force is very effective for commercialization of products.

[Tilt Direction]

If the lens block 101 is to be manually turned in the tilt direction indicated with arrows in FIG. 2, the elastic force of the bent portion 106 a of the tilt plate spring 106 serves as a load. If the lens block 101 is turned by a force equal to or greater than the load and one's hand is released from the lens block 101 when the lens 108 c faces a desired direction, the lens 108 c is stopped at the position. The force for holding the lens block 101 in this state corresponds to the elastic force of the bent portion 106 a of the tilt plate spring 106.

The elastic force is increased or decreased by the plurality of methods as described above, which are simple. In the embodiment, the elastic force is studied as the rotational moment of the lens block 101 and set at 10 to 40 Nmm. This value is determined depending on the weight, size and the like of the lens block 101. Therefore, the fact that there is a plurality of the methods of increasing or decreasing the elastic force is very effective for commercialization of products.

According to the embodiment described above, the security camera 100 is such that the mechanism for shifting the lens 108 c in the tilt and pan directions does not have large component parts and can be realized by a small number of component parts compared with traditional security cameras. In addition, the security camera 100 does not need a fastening screw and is assembled only by overlapping the component parts from one direction and more easily than before. As a result, the present embodiment can realize the security camera reduced in cost and in size.

The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2010-241255 filed in the Japan Patent Office on Oct. 27, 2010, the entire content of which is hereby incorporated by reference.

It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alternations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof. 

What is claimed is:
 1. An imaging device comprising: a lens case on which a lens is installed; a columnar member having a central axis coincidental with a rotational axis of the lens case and formed on a lateral surface of the lens case, the rotational axis extending in a tilt direction being an in-plane direction perpendicular to a horizontal direction; a base supporting the lens case so as to be turnable in the tilt direction; and a plate spring secured to the base and pressing a circumferential surface of the columnar member toward the base by elastic force, said plate spring having a plate-like insertion portion, and the base having a first opening adapted to receive the insertion portion inserted thereinto to secure the plate spring.
 2. The imaging device according to claim 1, wherein the plate spring has a first bent portion pressing the circumferential surface of the colunmar member toward the base.
 3. The imaging device according to claim 1, further comprising: a cover allowing the lens to be exposed and covering the lens case, the columnar member, the base and the plate spring; wherein the plate spring secures the cover to the base by elastic force.
 4. The imaging device according to claim 3, wherein the cover supports the lens case turnably in the tilt direction.
 5. The imaging device according to claim 3, wherein the plate spring has a second bent portion securing the cover to the base.
 6. The imaging device according to claim 3, wherein the cover has a second opening adapted to receive the plate spring inserted thereinto and a guide portion guiding the plate spring to the second opening.
 7. A mechanism having a plate spring comprising: a first spring portion of the plate spring pressing a circumferential surface of a columnar member toward a base supporting a lens case, the columnar member being formed on a lateral surface of the lens case on which a lens is installed; and a second spring portion of the plate spring securing a cover to the base by elastic force, the cover covering the lens case, the columnar member and the base while allowing the lens to be exposed.
 8. The mechanism having a plate spring according to claim 7, further comprising: a plate-like insertion portion of the plate spring inserted into a first opening formed in the base. 